The activation by K⁺ and occurrence of pyruvic phosphoferase in different species

Effects of Temperature and Activating Cations on the Fluorescence of Pyruvate Kinase*

“…It is interesting that the polarization of pyruvate kinase in 0.101 m TMAC1 at 30°( Figure 4) is also essentially identical with that of dissociated lactic dehydrogenase (Anderson and Weber, 1966). Brewer and Weber (1966) reported that the addition of Mg2+ to yeast enolase resulted in an increase in polarization at all exciting wavelengths between 240 and 300 µ. A general increase in polarization was also observed with pyruvate kinase after the addition of activating cations (Figure 4) or when the solution temperature was lowered (Figure 5).…”

“…This increase, apparent at all exciting wavelengths, indicates less freedom in the rotation of the tryptophyl residues suggesting the conversion to a more compact molecule during the transformation. Sedimentation data are also in support of a more compact protein molecule following the interaction of activating cations with yeast enolase (Brewer and Weber, 1966) or pyruvate kinase (F. J. Kayne and C. H. Suelter, 1967, unpublished data).…”

“…P L• yruvate kinase (EC 2.7.1.40), regardless of source of isolation (Boyer, 1953), requires both monovalent and divalent cations for catalytic activity. Studies of the interactions of these cations with rabbit muscle pyruvate kinase by a variety of techniques (Suelter et al, 1966;Cohn, 1965, 1966;Sorger et al, 1965) indicates that the enzyme-metal complex has a conformation which is different from that of free enzyme.…”

Mechanism of Action of Micronutrient Elements in Enzyme Systems

“…The double metal requirement for maximum enzyme activity lends support to the concept of "metallo-substrates" discussed by Najjar (107). Recently Boyer (19) has studied in detail the metal activation of pyruvic acid kinase from a variety of marine organisms and concluded that K+ activation is a general phenomenon for this enzyme. Previously, Kachmar & Boyer (69) were able to show that K+, in addition to Mg,++ was an absolute requirement for this enzyme from rabbit.…”

Enzymes Activated by Monovalent Cations

“…Subclass where X is 0, NH, or CHs Rumen microorganism (33) Bacillus polymyxa (34), Rhodopseudomonas spheroides (35) Rat heart (35,36), rabbit heart (37) Streptococcus faecalis (38) Pigeon liver (39), Saccharomyces cerevisiae (40) Tobacco leaves (41) Phaseolus vulgaris (seedlings) (42), Triticum vulgare (wheat germ) (43) Escherichia coli (44) S. cerevisiae (45), rat liver (45) Human erythrocytes (46), chicken liver (46), leukocytes (47), Aerobacter aerogenes (48), spinach leaves (49) E. coli (50), rat liver (51) Bovine liver (52), pig heart (53) Rat liver (54), pancreas (55) E. coli (56) E. coli (57) Rabbit muscle (58), Amia colva (58) (enzyme in nine other marine organisms was activated by K+), Zea mays (seed) (59), Cucurbita pepo (seed) (60), rat brain (61), yeast (62), mouse liver (63) Aspergillus niger (65) Bacteroides symbiosus (66) Bovine liver (67) Rabbit muscle (68), yeast (69), sheep brain (70), rat brain (71), slime mold (72) Pigeon liver (73) reactions E. coli (74) Bacillus subtilis (75) Rat liver (76), E. coli (77) Sheep liver (76), yeast (78) Rhodopseudomonas spheroides (79) A. aerogenes (80) Clostridiuim …”